Crankshafts ordinarily have main journals which are supported in main bearings and radial crankarms which connect the ends of the main journals to the ends of crankpins. One or more of the main journals can have a main cross passage communicating with a connecting passage which extends through a crank arm to the the outer surface of a crankpin. A portion of the oil film which surrounds each main journal can flow into the main cross passage from where it is supplied to the connecting passage. The oil can then flow through the connecting passage to the outer surface of the crankpin for lubrication. The flow of oil from the outer surface of the main journal into the main cross passage can cause a reduction in the minimum oil film thickness between the main journal and main bearing.